3(x+y)-4(x-y)=4
1.((y+2x)(-2x+y)+4(x+2y)^2)/3y 2.(2(x-y)^3-8(x-y)^2(x+y)+6y(
3(x+y)-4(x-y)=4
(x+y/4)+(x-y/5)=3
(x-4y)分之(3x)+(4y-x)分之(x+y)-(x-4y)分之(7y)
(X-3Y)(X+3Y)-(X+2Y)(X-4Y)-(2X-Y)2的平方
已知y=根号下(x-4)+根号下(4-x)+3,求代数式(x-y+4xy/x-y)(x+y-4xy/x+y)?
现化简,再求值:(3x-y)(x+2y)-2(x-3y)·(x-4y),其中x=4,y=1.5
先化简在求值 (x+5y)(x+4y)-(x-y)(x+y),其中,x=-2又2/3,y=3/7
先化简,再求值:(x+y)(2x-y)-(x+2y)(x-2y),其中x=3,y=4.
已知x+y+2(-x-y+1)=3(1-y-x)-4(y+x-1),则x+y等于( )
解方程组:(0.2x+0.1y)/2- (4x-y)/10=(x-y)/5+ (3x+0.5y)/30 (3x+2y-1
设动点P与P'的坐标为(X,Y)(X',Y')它们满足X'=3X+2Y+1,Y'=X+4Y-3.